Engaging Populism? The Popularity of European Populist Political Parties on Facebook and Twitter, 2010-2020

Scholars have argued that populists disproportionately benefit from social media, and there is evidence that they attract more engagement than other politicians and parties in several countries. We systematically evaluate the relationship between populism and online popularity using a novel dataset covering over four hundred parties active on Facebook and Twitter in thirty European countries between 2010 and 2020. We use Bayesian hierarchical models to assess the relationship between populism and three types of engagement on each platform. We find that populists received more engagement than other parties on Facebook, but there was no consistent relationship on Twitter. Among these parties, only right-wing populist parties had any widespread advantages. Our results highlight considerable heterogeneity across countries and over time, providing new insight into the scope and scale of populists' online popularity. This includes evidence that left-wing and centrist parties attracted more engagement in a handful of countries. We evaluate several explanations for these results, finding that negative macroeconomic indicators and increased migration are positively correlated with populist engagement, while internet and social media adoption have mixed impacts that benefit right-wing populists.